The wife did it. She never saw the business partner, since he was alone outside to escape the crowd and gather his thoughts. She worked in the same office as her husband, and saw the email drafted. She has been jealous of the secretary since her husband met her in college, since she has been with her husband since high school. After seeing the email, that was her last straw. She killed him with the letter opener after his partner left and escaped the scene before anyone saw her and did not have the chance to remove the email. Photo Credits:https://st.hzcdn.com/simgs/pictures/home-offices/home-office-grand-home-automation-img~a67131350113f5c7_9-3701-1-1a796c5.jpg https://i.pinimg.com/originals/65/5a/3e/655a3eff8f00f507e2688289f269d989.png https://media.istockphoto.com/photos/wax-seal-and-old-letters-picture-id500801690?k=20&m=500801690&s=612x612&w=0&h=Aw8-WoTtyyZJ5rhhFIpk5M1zq2bHCCP-XcAgyjRZX68=